The present invention relates to digital recording/reproducing apparatus for recording/reproducing a plurality of digital field or frame data on or from a plurality of tracks of a recording medium such as a magnetic tape.
Conventionally, in a helical scan type digital recording/reproducing apparatus for recording/reproducing digital data such as digitized video and audio signals on/from recording tracks formed obliquely on a magnetic tape, one field or frame data is recorded in a plurality of tracks for massive information recording purposes. That is, when controlling a capstan to supply data on the magnetic tape by one field or one frame at the time of a special reproduction such as frame reproduction and slow reproduction, the magnetic tape is gradually fed at a speed lower than the normal reproduction speed by means of a JOG dial or the like which is capable of freely operating the capstan speed, while a plurality of tracks on the magnetic tape are scanned plural times by a magnetic head so that the data of the plurality of tracks obtained by the magnetic head are stored in a memory of a signal processing circuit and a picture is outputted when the data corresponding to one field or one frame is stored in the memory. FIG. 12 is an illustration of an arrangement of a conventional digital recording/reproducing apparatus. In FIG. 12, in the normal reproduction state, the user operates a JOG dial operation allowing button 12 of a mode changing switch 10 to allow the operation of the JOG dial 11. In response to the operation of the JOG dial operation allowing button 12, a system controller 3 controls a motor-controlling servo circuit 4 through a communication signal line 9 so that a capstan 7 takes a JOG dial operation mode. When taking the JOG dial operation mode, the system controller 3 sets the JOG dial 11 to an actually operable mode, thereafter operating the JOG dial 11 by the user. In response to a signal from the JOG dial 11, the system controller 3 controls the servo circuit 4 through the communication signal line 9 so that the capstan 7 is rotated at a speed lower as compared with the normal reproduction speed. While the capstan 7 is rotating at the lower speed, a rotary head 6 (two heads in the illustration) picks up (reproduces) data on a magnetic tape 8. Here, since the capstan 7 is rotating at the lower speed, as illustrated in FIG. 13 the scanning locus 22 of the rotary head 6 with respect to the magnetic tape 8 is shifted from the scanning locus 21 in the normal reproduction state so that the rotary head 6 scans a plurality of tracks on the magnetic tape 8 to continuously pick up only a portion of data of each of the plurality of tracks. The data picked up by the rotary head 6 are supplied to a signal processing circuit 1 and then stored in a memory 2. FIG. 14 is an illustration of the flow of data from the magnetic tape 8 to the memory 2 where numeral 31 represents the speed variation of the capstan 7, 32 designates the data amount within the memory 2, 33 depicts the data amount corresponding one frame or one field, and 34 denotes the timing that the data corresponding to one frame or one field are stored in the memory 2. When the data corresponding to one frame are stored in the memory 2, the frame data are outputted as one picture. Up to that time, the user gradually and continuously operates the JOG dial 11 while watching the output picture until the output picture is changed over. When the output picture is changed over, the feed of one frame is completed. Accordingly, the user stops to operate the JOG dial 11 or further operates the JOG dial 11 if required.
There is a problem which arises with such a conventional technique, however, in that, since for the frame operation the servo circuit 4, the system controller 3 and others operate independently of the signal processing circuit 1, the stopping of the capstan motor can be realized only by the decision of the user according to the output picture, i.e., only by the operation of the JOG dial 11 or the like. This is inconvenient for the user.